Zerocopy

api/libBareMetal.asm

@@ -7,13 +7,13 @@
 
 ; Kernel functions
 b_input			equ 0x0000000000100010	; Scans keyboard for input. OUT: AL = 0 if no key pressed, otherwise ASCII code
-b_output		equ 0x0000000000100018	; Displays a number of characters. IN: RSI = message location, RCX = number of characters
+b_output		equ 0x0000000000100018	; Displays a number of characters. IN: RSI = Memory address of message, RCX = number of characters
 
-b_net_tx		equ 0x0000000000100020	; Transmit a packet via a network interface. IN: RSI = Memory location where packet is stored, RCX = Length of packet, RDX = Device
-b_net_rx		equ 0x0000000000100028	; Polls the network interface for received packet. IN: RDI = Memory location where packet will be stored, RDX = Device. OUT: RCX = Length of packet
+b_net_tx		equ 0x0000000000100020	; Transmit a packet via a network interface. IN: RSI = Memory address of where packet is stored, RCX = Length of packet, RDX = Device
+b_net_rx		equ 0x0000000000100028	; Polls the network interface for received packet. IN: RDX = Device. OUT: RDI = Memory address of where packet was stored, RCX = Length of packet
 
-b_nvs_read		equ 0x0000000000100030	; Read data from a non-volatile storage device. IN: RAX = Starting sector, RCX = Number of sectors to read, RDX = Device, RDI = Memory location to store data
-b_nvs_write		equ 0x0000000000100038	; Write data to a non-volatile storage device. IN: RAX = Starting sector, RCX = Number of sectors to write, RDX = Device, RSI = Memory location of data to store
+b_nvs_read		equ 0x0000000000100030	; Read data from a non-volatile storage device. IN: RAX = Starting sector, RCX = Number of sectors to read, RDX = Device, RDI = Memory address to store data
+b_nvs_write		equ 0x0000000000100038	; Write data to a non-volatile storage device. IN: RAX = Starting sector, RCX = Number of sectors to write, RDX = Device, RSI = Memory address of data to store
 
 b_system		equ 0x0000000000100040	; Configure system. IN: RCX = Function, RAX = Variable 1, RDX = Variable 2. OUT: RAX = Result
 
@@ -35,7 +35,8 @@ SCREEN_X_GET		equ 0x21
 SCREEN_Y_GET		equ 0x22
 SCREEN_PPSL_GET		equ 0x23
 SCREEN_BPP_GET		equ 0x24
-MAC_GET			equ 0x30
+NET_STATUS		equ 0x30
+NET_CONFIG		equ 0x31
 BUS_READ		equ 0x50
 BUS_WRITE		equ 0x51
 STDOUT_SET		equ 0x52

api/libBareMetal.c

@@ -30,7 +30,7 @@ void b_net_tx(void *mem, u64 len, u64 iid) {
 
 u64 b_net_rx(void *mem, u64 iid) {
 	u64 tlong;
-	asm volatile ("call *0x00100028" : "=c"(tlong) : "D"(mem), "d"(iid));
+	asm volatile ("call *0x00100028" : "=D"(mem), "=c"(tlong) : "d"(iid));
 	return tlong;
 }
 

api/libBareMetal.h

@@ -48,7 +48,8 @@ u64 b_system(u64 function, u64 var1, u64 var2);
 #define SCREEN_Y_GET		0x22
 #define SCREEN_PPSL_GET		0x23
 #define SCREEN_BPP_GET		0x24
-#define MAC_GET			0x30
+#define NET_STATUS		0x30
+#define NET_CONFIG		0x31
 #define BUS_READ		0x50
 #define BUS_WRITE		0x51
 #define STDOUT_SET		0x52

src/drivers/net/i8254x.asm

@@ -23,16 +23,13 @@ net_i8254x_init:
 	add rdi, rax
 
 	mov ax, 0x8254			; Driver tag for i8254x
-	stosw
-	add rdi, 14
+	mov [rdi+nt_ID], ax
 
 	; Get the Base Memory Address of the device
 	mov al, 0			; Read BAR0
 	call os_bus_read_bar
-	stosq				; Save the base
+	mov [rdi+nt_base], rax		; Save the base
 	push rax			; Save the base for gathering the MAC later
-	mov rax, rcx
-	stosq				; Save the length
 
 	; Set PCI Status/Command values
 	mov dl, 0x01			; Read Status/Command
@@ -44,7 +41,8 @@ net_i8254x_init:
 
 	; Get the MAC address
 	pop rsi				; Restore the base
-	sub rdi, 24			; 8 bytes into net table entry
+	push rdi
+	add rdi, 8
 	mov eax, [rsi+i8254x_RAL]	; RAL
 	stosb
 	shr eax, 8
@@ -57,31 +55,32 @@ net_i8254x_init:
 	stosb
 	shr eax, 8
 	stosb
+	pop rdi
 
 	; Set base addresses for TX and RX descriptors
 	xor ecx, ecx
 	mov cl, byte [os_net_icount]
 	shl ecx, 15
 
-	add rdi, 0x22
 	mov rax, os_tx_desc
 	add rax, rcx
-	stosq
+	mov [rdi+nt_tx_desc], rax
 	mov rax, os_rx_desc
 	add rax, rcx
-	stosq
+	mov [rdi+nt_rx_desc], rax
 
 	; Reset the device
 	xor edx, edx
 	mov dl, [os_net_icount]
 	call net_i8254x_reset
 
 	; Store call addresses
-	sub rdi, 0x20
+	mov rax, net_i8254x_config
+	mov [rdi+nt_config], rax
 	mov rax, net_i8254x_transmit
-	stosq
+	mov [rdi+nt_transmit], rax
 	mov rax, net_i8254x_poll
-	stosq
+	mov [rdi+nt_poll], rax
 
 net_i8254x_init_error:
 
@@ -215,6 +214,34 @@ net_i8254x_reset_nextdesc:
 ; -----------------------------------------------------------------------------
 
 
+; -----------------------------------------------------------------------------
+; net_i8254x_config - 
+;  IN:	RAX = Base address to store packets
+;	RDX = Interface ID
+; OUT:	Nothing
+net_i8254x_config:
+	push rdi
+	push rcx
+	push rax
+
+	mov rdi, [rdx+nt_rx_desc]
+	mov ecx, i8254x_MAX_DESC
+	call os_virt_to_phys
+net_i8254x_config_next_record:
+	stosq
+	add rdi, 8
+	add rax, 2048
+	dec ecx
+	cmp ecx, 0
+	jnz net_i8254x_config_next_record
+
+	pop rax
+	pop rcx
+	pop rdi
+	ret
+; -----------------------------------------------------------------------------
+
+
 ; -----------------------------------------------------------------------------
 ; net_i8254x_transmit - Transmit a packet via an Intel 8254x NIC
 ;  IN:	RSI = Location of packet
@@ -270,9 +297,9 @@ net_i8254x_transmit:
 
 ; -----------------------------------------------------------------------------
 ; net_i8254x_poll - Polls the Intel 8254x NIC for a received packet
-;  IN:	RDI = Location to store packet
-;	RDX = Interface ID
-; OUT:	RCX = Length of packet
+;  IN:	RDX = Interface ID
+; OUT:	RDI = Location of stored packet
+;	RCX = Length of packet
 ; Note:	RDESC Descriptor Format:
 ;	First Qword:
 ;	Bits 63:0 - Buffer Address
@@ -283,8 +310,8 @@ net_i8254x_transmit:
 ;	Bits 47:40 - Errors
 ;	Bits 63:48 - Special
 net_i8254x_poll:
-	push rdi
 	push rsi			; Used for the base MMIO of the NIC
+	push rbx
 	push rax
 
 	mov rdi, [rdx+nt_rx_desc]
@@ -293,8 +320,9 @@ net_i8254x_poll:
 	; Calculate the descriptor to read from
 	mov eax, [rdx+nt_rx_head]	; Get rx_lasthead
 	shl eax, 4			; Quick multiply by 16
-	add eax, 8			; Offset to bytes received
 	add rdi, rax			; Add offset to RDI
+	mov rbx, [rdi]
+	add rdi, 8			; Offset to bytes received
 	; Todo: read all 64 bits. check status bit for DD
 	xor ecx, ecx			; Clear RCX
 	mov cx, [rdi]			; Get the packet length
@@ -303,6 +331,7 @@ net_i8254x_poll:
 
 	xor eax, eax
 	stosq				; Clear the descriptor length and status
+	mov rdi, rbx
 
 	; Increment i8254x_rx_lasthead and the Receive Descriptor Tail
 	mov eax, [rdx+nt_rx_head]	; Get rx_lasthead
@@ -315,16 +344,10 @@ net_i8254x_poll:
 	and eax, i8254x_MAX_DESC - 1
 	mov [rsi+i8254x_RDT], eax	; Write the updated Receive Descriptor Tail
 
-	pop rax
-	pop rsi
-	pop rdi
-	ret
-
 net_i8254x_poll_end:
-	xor ecx, ecx
 	pop rax
+	pop rbx
 	pop rsi
-	pop rdi
 	ret
 ; -----------------------------------------------------------------------------
 
@@ -346,8 +369,7 @@ net_i8254x_poll_end:
 
 
 ; Constants
-i8254x_MAX_PKT_SIZE	equ 16384
-i8254x_MAX_DESC		equ 16		; Must be 16, 32, 64, 128, etc.
+i8254x_MAX_DESC		equ 2048	; Must be 16, 32, 64, 128, etc. Each descriptor is 16 bytes
 
 ; Register list (13.2) (All registers should be accessed as 32-bit values)
 

src/drivers/net/i8257x.asm

@@ -26,16 +26,13 @@ net_i8257x_init:
 	add rdi, rax
 
 	mov ax, 0x8257			; Driver tag for i8257x
-	stosw
-	add rdi, 14
+	mov [rdi+nt_ID], ax
 
 	; Get the Base Memory Address of the device
 	mov al, 0			; Read BAR0
 	call os_bus_read_bar
-	stosq				; Save the base
+	mov [rdi+nt_base], rax		; Save the base
 	push rax			; Save the base for gathering the MAC later
-	mov rax, rcx
-	stosq				; Save the length
 
 	; Set PCI Status/Command values
 	mov dl, 0x01			; Read Status/Command
@@ -47,7 +44,8 @@ net_i8257x_init:
 
 	; Get the MAC address
 	pop rsi				; Restore the base
-	sub rdi, 24			; 8 bytes into net table entry
+	push rdi
+	add rdi, 8
 	mov eax, [rsi+i8257x_RAL]	; RAL
 	stosb
 	shr eax, 8
@@ -60,31 +58,32 @@ net_i8257x_init:
 	stosb
 	shr eax, 8
 	stosb
+	pop rdi
 
 	; Set base addresses for TX and RX descriptors
 	xor ecx, ecx
 	mov cl, byte [os_net_icount]
 	shl ecx, 15
 
-	add rdi, 0x22
 	mov rax, os_tx_desc
 	add rax, rcx
-	stosq
+	mov [rdi+nt_tx_desc], rax
 	mov rax, os_rx_desc
 	add rax, rcx
-	stosq
+	mov [rdi+nt_rx_desc], rax
 
 	; Reset the device
 	xor edx, edx
 	mov dl, [os_net_icount]
 	call net_i8257x_reset
 
 	; Store call addresses
-	sub rdi, 0x20
+	mov rax, net_i8257x_config
+	mov [rdi+nt_config], rax
 	mov rax, net_i8257x_transmit
-	stosq
+	mov [rdi+nt_transmit], rax
 	mov rax, net_i8257x_poll
-	stosq
+	mov [rdi+nt_poll], rax
 
 net_i8257x_init_error:
 
@@ -217,6 +216,34 @@ net_i8257x_reset_nextdesc:
 ; -----------------------------------------------------------------------------
 
 
+; -----------------------------------------------------------------------------
+; net_i8257x_config - 
+;  IN:	RAX = Base address to store packets
+;	RDX = Interface ID
+; OUT:	Nothing
+net_i8257x_config:
+	push rdi
+	push rcx
+	push rax
+
+	mov rdi, [rdx+nt_rx_desc]
+	mov ecx, i8257x_MAX_DESC
+	call os_virt_to_phys
+net_i8257x_config_next_record:
+	stosq
+	add rdi, 8
+	add rax, 2048
+	dec ecx
+	cmp ecx, 0
+	jnz net_i8257x_config_next_record
+
+	pop rax
+	pop rcx
+	pop rdi
+	ret
+; -----------------------------------------------------------------------------
+
+
 ; -----------------------------------------------------------------------------
 ; net_i8257x_transmit - Transmit a packet via an Intel 8257x NIC
 ;  IN:	RSI = Location of packet
@@ -285,8 +312,8 @@ net_i8257x_transmit:
 ;	Bits 47:40 - Errors
 ;	Bits 63:48 - VLAN
 net_i8257x_poll:
-	push rdi
 	push rsi			; Used for the base MMIO of the NIC
+	push rbx
 	push rax
 
 	mov rdi, [rdx+nt_rx_desc]
@@ -295,8 +322,9 @@ net_i8257x_poll:
 	; Calculate the descriptor to read from
 	mov eax, [rdx+nt_rx_head]	; Get rx_lasthead
 	shl eax, 4			; Quick multiply by 16
-	add eax, 8			; Offset to bytes received
 	add rdi, rax			; Add offset to RDI
+	mov rbx, [rdi]
+	add rdi, 8			; Offset to bytes received
 	; Todo: read all 64 bits. check status bit for DD
 	xor ecx, ecx			; Clear RCX
 	mov cx, [rdi]			; Get the packet length
@@ -305,6 +333,7 @@ net_i8257x_poll:
 
 	xor eax, eax
 	stosq				; Clear the descriptor length and status
+	mov rdi, rbx
 
 	; Increment i8257x_rx_lasthead and the Receive Descriptor Tail
 	mov eax, [rdx+nt_rx_head]	; Get rx_lasthead
@@ -317,23 +346,16 @@ net_i8257x_poll:
 	and eax, i8257x_MAX_DESC - 1
 	mov [rsi+i8257x_RDT], eax	; Write the updated Receive Descriptor Tail
 
-	pop rax
-	pop rsi
-	pop rdi
-	ret
-
 net_i8257x_poll_end:
-	xor ecx, ecx
 	pop rax
+	pop rbx
 	pop rsi
-	pop rdi
 	ret
 ; -----------------------------------------------------------------------------
 
 
 ; Constants
-i8257x_MAX_PKT_SIZE	equ 16384
-i8257x_MAX_DESC		equ 16		; Must be 16, 32, 64, 128, etc.
+i8257x_MAX_DESC		equ 2048	; Must be 16, 32, 64, 128, etc. Each descriptor is 16 bytes
 
 ; Register list (13.3) (All registers should be accessed as 32-bit values)